<template>
  <div id="demo">
    <!-- 遮罩层 -->
    <div class="container" v-show="panel">
      <div>
        <img id="image" :src="url" alt="Picture">
      </div>
      <button type="button" id="button" @click="crop">确定</button>
    </div>

    <div style="padding:20px;">
      <div class="show">
        <div class="picture" :style="'backgroundImage:url('+headerImage+')'">
        </div>
      </div>
      <div style="margin-top:20px;">
        <input type="file" id="change" accept="image" @change="change">
        <label for="change"></label>
      </div>
    </div>
  </div>
</template>
<script>
  import Cropper from 'cropperjs'
  export default {
    components: {

    },
    data () {
      return {
        headerImage:'',
        picValue:'',
        cropper:'',
        croppable:false,
        panel:false,
        url:''
      }
    },
    mounted () {
      //初始化这个裁剪框
      var self = this;
      var image = document.getElementById('image');
      this.cropper = new Cropper(image, {
        aspectRatio: 1,
        viewMode: 1,
        background:false,
        zoomable:false,
        ready: function () {
          self.croppable = true;
        }
      });
    },
    methods: {
      getObjectURL (file) {
        var url = null ;
        if (window.createObjectURL!=undefined) { // basic
          url = window.createObjectURL(file) ;
        } else if (window.URL!=undefined) { // mozilla(firefox)
          url = window.URL.createObjectURL(file) ;
        } else if (window.webkitURL!=undefined) { // webkit or chrome
          url = window.webkitURL.createObjectURL(file) ;
        }
        return url ;
      },
      change (e) {
        let files = e.target.files || e.dataTransfer.files;
        if (!files.length) return;
        this.panel = true;
        this.picValue = files[0];

        this.url = this.getObjectURL(this.picValue);
        //每次替换图片要重新得到新的url
        if(this.cropper){
          this.cropper.replace(this.url);
        }
        this.panel = true;

      },
      crop () {
        this.panel = false;
        var croppedCanvas;
        var roundedCanvas;

        if (!this.croppable) {
          return;
        }
        // Crop
        croppedCanvas = this.cropper.getCroppedCanvas();
        console.log(this.cropper)
        // Round
        roundedCanvas = this.getRoundedCanvas(croppedCanvas);

        this.headerImage = roundedCanvas.toDataURL();
        this.postImg()

      },
      getRoundedCanvas (sourceCanvas) {

        var canvas = document.createElement('canvas');
        var context = canvas.getContext('2d');
        var width = sourceCanvas.width;
        var height = sourceCanvas.height;

        canvas.width = width;
        canvas.height = height;

        context.imageSmoothingEnabled = true;
        context.drawImage(sourceCanvas, 0, 0, width, height);
        context.globalCompositeOperation = 'destination-in';
        context.beginPath();
//        context.arc(width / 2, height / 2, Math.min(width, height) / 2, 0, 2 * Math.PI, true);
        context.rect(0,0,width, height);
        context.fill();

        return canvas;
      },
      postImg () {
        //这边写图片的上传
      }
    }
  }
</script>
<style>
  #demo #button {
    position: absolute;
    right: 10px;
    top: 10px;
    width: 80px;
    height: 40px;
    border:none;
    border-radius: 5px;
    background:white;
  }
  #demo .show {
    width: 100px;
    height: 100px;
    overflow: hidden;
    position: relative;
    /*border-radius: 50%;*/
    border: 1px solid #d5d5d5;
  }
  #demo .picture {
    width: 100%;
    height: 100%;
    overflow: hidden;
    background-position: center center;
    background-repeat: no-repeat;
    background-size: cover;
  }
  #demo .container {
    z-index: 99;
    position: fixed;
    padding-top: 60px;
    left: 0;
    top: 0;
    right: 0;
    bottom: 0;
    background:rgba(0,0,0,1);
  }
  #demo #image {
    max-width: 100%;
  }
  .cropper-view-box,.cropper-face {
    /*border-radius: 50%;*/
  }
  /*!
   * Cropper.js v1.0.0-rc
   * https://github.com/fengyuanchen/cropperjs
   *
   * Copyright (c) 2017 Fengyuan Chen
   * Released under the MIT license
   *
   * Date: 2017-03-25T12:02:21.062Z
   */
  .cropper-container {
    font-size: 0;
    line-height: 0;
    position: relative;
    -webkit-user-select: none;
    -moz-user-select: none;
    -ms-user-select: none;
    user-select: none;
    direction: ltr;
    -ms-touch-action: none;
    touch-action: none
  }

  .cropper-container img {
    /* Avoid margin top issue (Occur only when margin-top <= -height) */
    display: block;
    min-width: 0 !important;
    max-width: none !important;
    min-height: 0 !important;
    max-height: none !important;
    width: 100%;
    height: 100%;
    image-orientation: 0deg
  }
  .cropper-wrap-box,
  .cropper-canvas,
  .cropper-drag-box,
  .cropper-crop-box,
  .cropper-modal {
    position: absolute;
    top: 0;
    right: 0;
    bottom: 0;
    left: 0;
  }
  .cropper-wrap-box {
    overflow: hidden;
  }
  .cropper-drag-box {
    opacity: 0;
    background-color: #fff;
  }
  .cropper-modal {
    opacity: .5;
    background-color: #000;
  }
  .cropper-view-box {
    display: block;
    overflow: hidden;
    width: 100%;
    height: 100%;
    outline: 1px solid #39f;
    outline-color: rgba(51, 153, 255, 0.75);
  }

  .cropper-dashed {
    position: absolute;
    display: block;
    opacity: .5;
    border: 0 dashed #eee
  }
  .cropper-dashed.dashed-h {
    top: 33.33333%;
    left: 0;
    width: 100%;
    height: 33.33333%;
    border-top-width: 1px;
    border-bottom-width: 1px
  }
  .cropper-dashed.dashed-v {
    top: 0;
    left: 33.33333%;
    width: 33.33333%;
    height: 100%;
    border-right-width: 1px;
    border-left-width: 1px
  }
  .cropper-center {
    position: absolute;
    top: 50%;
    left: 50%;
    display: block;
    width: 0;
    height: 0;
    opacity: .75
  }
  .cropper-center:before,
  .cropper-center:after {
    position: absolute;
    display: block;
    content: ' ';
    background-color: #eee
  }
  .cropper-center:before {
    top: 0;
    left: -3px;
    width: 7px;
    height: 1px
  }
  .cropper-center:after {
    top: -3px;
    left: 0;
    width: 1px;
    height: 7px
  }
  .cropper-face,
  .cropper-line,
  .cropper-point {
    position: absolute;
    display: block;
    width: 100%;
    height: 100%;
    opacity: .1;
  }
  .cropper-face {
    top: 0;
    left: 0;
    background-color: #fff;
  }
  .cropper-line {
    background-color: #39f
  }
  .cropper-line.line-e {
    top: 0;
    right: -3px;
    width: 5px;
    cursor: e-resize
  }
  .cropper-line.line-n {
    top: -3px;
    left: 0;
    height: 5px;
    cursor: n-resize
  }
  .cropper-line.line-w {
    top: 0;
    left: -3px;
    width: 5px;
    cursor: w-resize
  }
  .cropper-line.line-s {
    bottom: -3px;
    left: 0;
    height: 5px;
    cursor: s-resize
  }
  .cropper-point {
    width: 5px;
    height: 5px;

    opacity: .75;
    background-color: #39f
  }
  .cropper-point.point-e {
    top: 50%;
    right: -3px;
    margin-top: -3px;
    cursor: e-resize
  }
  .cropper-point.point-n {
    top: -3px;
    left: 50%;
    margin-left: -3px;
    cursor: n-resize
  }
  .cropper-point.point-w {
    top: 50%;
    left: -3px;
    margin-top: -3px;
    cursor: w-resize
  }
  .cropper-point.point-s {
    bottom: -3px;
    left: 50%;
    margin-left: -3px;
    cursor: s-resize
  }
  .cropper-point.point-ne {
    top: -3px;
    right: -3px;
    cursor: ne-resize
  }
  .cropper-point.point-nw {
    top: -3px;
    left: -3px;
    cursor: nw-resize
  }
  .cropper-point.point-sw {
    bottom: -3px;
    left: -3px;
    cursor: sw-resize
  }
  .cropper-point.point-se {
    right: -3px;
    bottom: -3px;
    width: 20px;
    height: 20px;
    cursor: se-resize;
    opacity: 1
  }
  @media (min-width: 768px) {
    .cropper-point.point-se {
      width: 15px;
      height: 15px
    }
  }
  @media (min-width: 992px) {
    .cropper-point.point-se {
      width: 10px;
      height: 10px
    }
  }
  @media (min-width: 1200px) {
    .cropper-point.point-se {
      width: 5px;
      height: 5px;
      opacity: .75
    }
  }
  .cropper-point.point-se:before {
    position: absolute;
    right: -50%;
    bottom: -50%;
    display: block;
    width: 200%;
    height: 200%;
    content: ' ';
    opacity: 0;
    background-color: #39f
  }
  .cropper-invisible {
    opacity: 0;
  }
  .cropper-bg {
    background-image: url('');
  }
  .cropper-hide {
    position: absolute;
    display: block;
    width: 0;
    height: 0;
  }
  .cropper-hidden {
    display: none !important;
  }
  .cropper-move {
    cursor: move;
  }
  .cropper-crop {
    cursor: crosshair;
  }
  .cropper-disabled .cropper-drag-box,
  .cropper-disabled .cropper-face,
  .cropper-disabled .cropper-line,
  .cropper-disabled .cropper-point {
    cursor: not-allowed;
  }
</style>
